Dryers kiln, high temperature

Indirect Rotary Calciners and Kilns These large-scale rotary processors are used for very high temperature operations. Operation is similar to that of rotary dryers. For additional information, refer to Perry s 7th Edition, pages 12-56 to 12-58. 

Rotary dryers can be operated at very high temperatures to accomplish various reactions in addition to or instead of simple drying these units are referred to as kilns. It is necessary to line the shell of rotary kilns with suitable refractory materials. 

High-temperature rotary drum lime and cement kilns are of similar configuration to rotary drum furnaces and dryers discussed in section 4.2, except that they are of higher temperature construction and longer. This is a very specialized field. (See Perry The Rotary Cement Kiln, reference 64.) A shaft-type lime kiln is shown in figure 1.11. 

Soils with high moisture or clay contents may reduce the efficiency of the LTTD system. Hot spots in the influent soils may cause fluctuations in the dryer temperature. The vaporized hydrocarbon concentration in the kiln must be kept below the lower explosive limit (LEL). 

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